A5107968582- Pulsars and Gravitational Waves Research
- Gamma-ray bursts and supernovae
- Geophysics and Gravity Measurements
- Astrophysical Phenomena and Observations
- Cosmology and Gravitation Theories
- Astrophysics and Cosmic Phenomena
- High-pressure geophysics and materials
- Atomic and Subatomic Physics Research
- Geophysics and Sensor Technology
- Neutrino Physics Research
- Seismic Waves and Analysis
- Particle physics theoretical and experimental studies
- Radio Astronomy Observations and Technology
- Dark Matter and Cosmic Phenomena
- Astronomy and Astrophysical Research
- Astronomical Observations and Instrumentation
- Galaxies: Formation, Evolution, Phenomena
- Statistical and numerical algorithms
- Stellar, planetary, and galactic studies
- Advanced Frequency and Time Standards
- Irrigation Practices and Water Management
- Magnetic confinement fusion research
- Adaptive optics and wavefront sensing
- Seismic Imaging and Inversion Techniques
- Nuclear and radioactivity studies
ARC Centre of Excellence for Gravitational Wave Discovery
2017-2024
Monash University
2017-2024
University of California, Berkeley
2020-2024
Australian Regenerative Medicine Institute
2019-2024
Federico Santa María Technical University
2023
California State University, Fullerton
2010-2022
Australian Research Council
2022
Lawrence Berkeley National Laboratory
2021-2022
California Institute of Technology
2014-2021
Istituto Nazionale di Fisica Nucleare, Trento Institute for Fundamental Physics And Applications
2020
Bayesian parameter estimation is fast becoming the language of gravitational-wave astronomy. It method by which data used to infer sources' astrophysical properties. We introduce a user-friendly inference library for astronomy, Bilby. This python code provides expert-level infrastructure with straightforward syntax and tools that facilitate use beginners. allows users perform accurate reliable on both real, freely-available from LIGO/Virgo, simulated data. provide suite examples analysis...
The Advanced LIGO and Virgo gravitational wave (GW) detectors will begin operation in the coming years, with compact binary coalescence events a likely source for first detections. waveforms emitted directly encode information about sources, including masses spins of objects. Recovering physical parameters sources from GW observations is key analysis task. This work describes LALInference software library Bayesian parameter estimation signals, which builds on several previous methods to...
ABSTRACT Gravitational waves provide a unique tool for observational astronomy. While the first LIGO–Virgo catalogue of gravitational-wave transients (GWTC-1) contains 11 signals from black hole and neutron star binaries, number observations is increasing rapidly as detector sensitivity improves. To extract information observed signals, it imperative to have fast, flexible, scalable inference techniques. In previous paper, we introduced bilby: modular user-friendly Bayesian library adapted...
Advanced LIGO-Virgo have reported a short gravitational-wave signal (GW190521) interpreted as quasicircular merger of black holes, one at least populating the pair-instability supernova gap, that formed remnant hole ${M}_{f}\ensuremath{\sim}142\text{ }\text{ }{M}_{\ensuremath{\bigodot}}$ luminosity distance ${d}_{L}\ensuremath{\sim}5.3\text{ }\mathrm{Gpc}$. With barely visible pre-merger emission, however, GW190521 merits further investigation dynamics and even very nature colliding objects....
ABSTRACT Understanding the properties of transient gravitational waves (GWs) and their sources is broad interest in physics astronomy. Bayesian inference standard framework for astrophysical measurement GW Usually, stochastic sampling algorithms are used to estimate posterior probability distributions over parameter spaces models describing experimental data. The most physically accurate typically come with a large computational overhead which can render data analsis extremely time...
Inferring astrophysical information from gravitational waves emitted by compact binaries is one of the key science goals gravitational-wave astronomy. In order to reach full scientific potential experiments, we require techniques mitigate cost Bayesian inference, especially as signal models and analyses become increasingly sophisticated detailed. Reduced-order (ROMs) waveforms can significantly reduce computational inference removing redundant computations. this paper, construct first...
We present the first surrogate model for gravitational waveforms from coalescence of precessing binary black holes. call this NRSur4d2s. Our methodology significantly extends recently introduced reduced-order and modeling techniques, is capable directly numerical relativity without introducing phenomenological assumptions or approximations to general relativity. Motivated by GW150914, LIGO's detection waves merging holes, built a set $276$ (NR) simulations with mass ratios $q \leq 2$,...
When binary black holes form in the field, it is expected that their orbits typically circularize before coalescence. In galactic nuclei and globular clusters, can dynamically. Recent results suggest $\ensuremath{\approx}5%$ of mergers clusters result from three-body interactions. These interactions are to induce significant orbital eccentricity $\ensuremath{\gtrsim}0.1$ when they enter Advanced LIGO Virgo band at a gravitational-wave frequency 10 Hz. Measurements hole therefore provide...
The physics of neutron stars can be studied with gravitational waves emitted from coalescing binary systems. Tidal effects become significant during the last few orbits and visible in gravitational-wave spectrum above 500 Hz. After merger, star remnant oscillates at frequencies 1 kHz collapse into a black hole. Gravitational-wave detectors sensitivity ~10^{-24} strain/sqHz 2-4 observe these oscillations source which is ~100 Mpc away. current observatories, such as LIGO Virgo, are limited by...
Inferring the astrophysical parameters of coalescing compact binaries is a key science goal upcoming advanced LIGO-Virgo gravitational-wave detector network and, more generally, astronomy. However, current approaches to parameter estimation for these detectors require computationally expensive algorithms. Therefore, there pressing need new, fast, and accurate Bayesian inference techniques. In this Letter, we demonstrate that reduced order modeling approach enables rapid be performed. By...
Bayesian inference is the workhorse of gravitational-wave astronomy, for example, determining mass and spins merging black holes, revealing neutron star equation state, unveiling population properties compact binaries. The science enabled by these inferences comes with a computational cost that can limit questions we are able to answer. This expected grow. As detectors improve, detection rate will go up, allowing less time analyze each event. Improvement in low-frequency sensitivity yield...
Roughly every 2-10 minutes, a pair of stellar mass black holes merge somewhere in the Universe. A small fraction these mergers are detected as individually resolvable gravitational-wave events by advanced detectors such LIGO and Virgo. The rest contribute to stochastic background. We derive statistically optimal search strategy for background unresolved binaries. Our method applies Bayesian parameter estimation all available data. Using Monte Carlo simulations, we demonstrate that is both...
Gravitational waves from binary neutron star coalescences contain rich information about matter at supranuclear densities encoded by the equation of state. We can measure state analyzing tidal interactions between stars, which is quantified deformability. Multiple merger events are required to probe over a range masses. The more included in analysis, stronger constraints on In this paper, we build previous work explore that LIGO and Virgo likely place combining first forty detections,...
Primordial gravitational waves are expected to create a stochastic background encoding information about the early Universe that may not be accessible by other means. However, primordial is obscured an astrophysical foreground consisting of from compact binaries. We demonstrate Bayesian method for estimating in presence foreground. Since and signal parameters estimated simultaneously, there no subtraction step, therefore we avoid contamination measurement, sometimes referred as...
Observations by LIGO--Virgo of binary black hole mergers suggest a possible anti-correlation between mass ratio ($q=m_{2}/m_{1}$) and the effective inspiral spin parameter $\chi_{\rm eff}$, mass-weighted projection onto orbital angular momentum (Callister et al. 2021). We show that such an can naturally occur for holes assembled in active galactic nuclei (AGN) due to spherical planar symmetry-breaking effects. describe phenomenological model which: 1) heavier live AGN disk tend up into...
Short gamma-ray bursts are believed to be produced by both binary neutron star (BNS) and star-black hole (NSBH) mergers. We use current estimates for the BNS NSBH merger rates calculate fraction of observable short through each channel. This allows us constrain $\mathcal{R}_{\rm{BNS}}=384^{+431}_{-213}{\rm{Gpc}^{-3} \rm{yr}^{-1}}$ ($90\%$ credible interval), a $16\%$ decrease in rate uncertainties from second LIGO--Virgo Gravitational-Wave Transient Catalog, GWTC-2. Assuming top-hat emission...
We present a rapid parameter estimation framework for compact binary coalescence (CBC) signals observed by the LIGO-Virgo-KAGRA (LVK) detector network. The goal of our is to enable optimal source localization neutron star (BNS) in low latency as well improve overall scalability full CBC analyses. Our based on reduced order quadrature (ROQ) technique and resolves its shortcomings utilizing multiple ROQ bases single run. have also developed sets various waveform models, IMRPhenomD,...
It is currently unknown how matter behaves at the extreme densities found within cores of neutron stars. Gravitational waves from binary star mergers encode rich information about stars' deformability, allowing equation state---and hence nuclear physics---to be inferred. Planned third-generation gravitational-wave observatories, having vastly improved sensitivity, are expected to provide tight constraints on state. We combine simulated observations by observatories Cosmic Explorer and...
Energy and angular distributions were measured for high-energy (${E}_{\ensuremath{\gamma}}>10$ MeV) gamma rays from collisions of $^{14}\mathrm{N}$ on Pb, Zn, C at beam energies $\frac{E}{A}=20, 30, \mathrm{and} 40$ MeV. The gamma-ray energy spectrum was to about 120 MeV $\frac{E}{A}=40$ 80 $\frac{E}{A}=20$ For ${E}_{\ensuremath{\gamma}}>20$ the spectra are roughly exponential with characteristic slope parameters ranging 10.0 + Pb 14.2 Reasonable agreement is obtained a model employing...
The T2K experiment studies oscillations of an off-axis muon neutrino beam between the J-PARC accelerator complex and Super-Kamiokande detector. Special emphasis is placed on measuring mixing angle theta_13 by observing electron appearance via sub-dominant to oscillation, searching for CP violation in lepton sector. includes a sophisticated, off-axis, near detector, ND280, situated 280 m downstream production target order measure properties understand better interactions at energy scale below...
The problem of reconstructing the sky position compact binary coalescences detected via gravitational waves is a central one for future observations with ground-based network gravitational-wave laser interferometers, such as Advanced LIGO and Virgo. Different techniques localization have been independently developed. They can be divided in two broad categories: fully coherent Bayesian techniques, which are high latency aimed at in-depth studies all parameters source, including position,...
Thanks to the recent discoveries of gravitational wave signals from binary black hole mergers by Advanced Laser Interferometer Gravitational Wave Observatory and Virgo, genuinely strong-field dynamics spacetime can now be probed, allowing for stringent tests general relativity (GR). One set consists parametrized deformations away GR in template waveform models then constraining size deviations, as was done detected previous work. In this paper, we construct reduced-order quadratures so speed...
Gravitational-wave observations of binary neutron star coalescences constrain the neutron-star equation state by enabling measurement tidal deformation each star. This is determined deformability parameter $\Lambda$, which was constrained using first gravitational-wave observation, GW170817. Now, with second star, GW190425, we can combine different measurements to obtain tighter constraints on state. In this paper, data from GW170817 and GW190425 place To facilitate calculation, derive...